Input Module

The input module allows you to check for user input from different devices like keyboard, mouse, gamepads and touchscreens.

Bullseye2D polls all information just before the update loop get called.

Keyboard

You can use Keyboard API to check key states.

To check for a specific Key, you can use the KeyCodes enum.

Here is a short example how to read the keyboard:

import 'package:bullseye2d/bullseye2d.dart';

class KeyboardDemo extends App {
  late BitmapFont font;

  @override
  onCreate() async {
    font = resources.loadFont("fonts/roboto/Roboto-Regular.ttf", 32);
  }

  @override
  onUpdate() {
    // get first char from the chard queue
    // Returns Char.empty if index is not found in queue
    Char char = keyboard.peekChar(0);
    if (char != Char.empty) {
      log("Char hit: ", char.symbol);
    }

    // Reads and consumes the next char in the input queue.
    char = keyboard.getChar();

    if (keyboard.keyUp(KeyCodes.W)) log("Ley 'W' was released!");

    // Use keyboard.keyHitCountSinceLastFrame(KeyCodes.W) if you want to 
    // know if 'W' was hit multiple times
    // since the last update
    if (keyboard.keyHit(KeyCodes.W)) log("Key 'W' is hit!");

    if (keyboard.keyDown(KeyCodes.W)) log("Key 'W' is currently pressed down!");
  }

  @override onRender() {
    gfx.clear(0, 0, 0, 1);
    gfx.drawText(font, "Press 'W' on your keyboard, watch the developer console ;)", 
      x: 25, 
      y: 25
    );
  }
}

main() {
  KeyboardDemo();
}

Mouse

The Mouse API handles mouse button presses, movement, wheel, and touch input. Coordinates are relative to the canvas (by default).

Example:

import 'package:bullseye2d/bullseye2d.dart';

class MouseDemo extends App {
  late BitmapFont font;

  @override
  onCreate() async {
    font = resources.loadFont("fonts/roboto/Roboto-Regular.ttf", 32);

    // set update Rate to display refresh rate
    updateRate = 0;
  }

  @override
  onUpdate() {
    double ty = 25;

    gfx.clear(0, 0, 0, 1);

    // Wait until app retrieved the first mouse coordinate
    if (mouse.x == -double.maxFinite) {
      gfx.drawText(font, "Please move your mouse over the canvas", x: 25, y: ty);
      return;
    }

    int mouseX = mouse.x.toInt();
    int mouseY = mouse.y.toInt();

    gfx.drawText(font, "Mouse Position $mouseX, $mouseY", x: 25, y: ty); ty += 30;

    if (mouse.mouseDown(MouseButton.Left)) {
      gfx.drawText(font, "Left Mouse Button was pressed", x: 25, y: ty); ty += 30;
    }

    if (mouse.mouseDown(MouseButton.Middle)) {
      gfx.drawText(font, "Middel Mouse Button was pressed", x: 25, y: ty); ty += 30;
    }

    if (mouse.mouseDown(MouseButton.Right)) {
      gfx.drawText(font, "Right Mouse Button was pressed", x: 25, y: ty); ty += 30;
    }
  }
}

main() {
  MouseDemo();
}

Gamepad

The Gamepad API supports up to 4 gamepads with a standard (XBOX Controller) mapping.

Example:

if (gamepad.countDevices() > 0) {
  if (gamepad.joyHit(0, GamepadButton.A)) {
    log("Gamepad 0: Button A pressed!");
  }
  double leftStickX = gamepad.joyX(0, Joystick.Left);
  if (leftStickX.abs() > 0.1) { // Apply a deadzone
    log("Gamepad 0: Left stick X = $leftStickX");
  }
}

Accelerometer

The Accelerometer API provides device motion data. Values are normalized (1.0 typically means 1G of acceleration).

The orientation of these axes depends on the device's screen orientation.

import 'package:bullseye2d/bullseye2d.dart';

class AccelDemo extends App {
  AccelDemo([super.config]);
  
  late BitmapFont font;

  @override
  onCreate() async {
    font = resources.loadFont("fonts/roboto/Roboto-Regular.ttf", 128);

    // set update Rate to display refresh rate
    updateRate = 0;
  }

  @override
  onUpdate() {
    gfx.clear(0, 0, 0, 1);
    gfx.drawText(font, "X: ${accel.x.toStringAsFixed(2)}", x: 25, y: 25);
    gfx.drawText(font, "Y: ${accel.y.toStringAsFixed(2)}", x: 25, y: 225);
    gfx.drawText(font, "Z: ${accel.z.toStringAsFixed(2)}", x: 25, y: 425);
  }
}

main() {
  // On iOS Devices it is requried to request permission to read out the
  // gyroscope, so we configure the app to handle it automatically for us
  // on the first user interaction
  AccelDemo(
    AppConfig(autoRequestAccelerometerPermission: true)
  );
}